1. Field of the Invention
The present invention relates to a joint for a storable tubular extendible member.
2. Description of the Related Art
It is known that if a flat strip of tempered spring steel, or other spring material, of much greater length than width, is elastically deformed into a tubular formation extending in the direction of its longitudinal axis, with substantial overlap of the longitudinal edges of the strip, then after a stress relieving heat treatment, the strip will recover to its tubular formation whenever free to do so. Consequently, the strip, if flattened to a tape-like state, may be tightly coiled at right angles to its longitudinal axis and will recover into its tubular formation as the tape-like strip is unrolled. Such a strip is known as a storable tubular extendible member, or STEM.
It is known to utilize two or more such tape-like strips which recover to form concentric tubes. The multi-tube configuration for a storable tubular extendible member provides a higher load bearing capability.
Storable tubular extendible members have found application in satellites as deployable antennae. However, these members would have broader application if they were jointed. The present invention therefore seeks to provide a joint for a storable tubular extendible member.